[member]

Since your a beginner, it is best to check out the SA:MP Wiki. It contains everything (nearly) that you will need to guide you trhough scripting. All the native functions are there, etc. Look through the tutorials if you want. https://sampwiki.blast.hk/wiki/Main_Page

When creating commands, i'd recommend using zcmd or dcmd.

Answers:

1. AddStaticVehicleEx is the same as AddStaticVehicleEx except it allows you to set a respawn time for when the vehicle is destroyed.
https://sampwiki.blast.hk/wiki/AddStaticVehicleEx

2. https://sampwiki.blast.hk/wiki/AddStaticPickup

3.
UnderOnGameModeInit

pawn Код:

new rand = random(sizeof(MainSpawns));

Example: (use the bit in bold)
AddPlayerClassEx( 15, 0, gRandomPlayerSpawns[rand][0],gRandomPlayerSpawns[rand][1],gRandomPlayerSpawns[rand][2], 0 26, 36, 28, 150, 0, 0 );

4. https://sampwiki.blast.hk/wiki/Creating_a_simple_Menu
or menu creator


Other stuff:
Basic command tutorial http://forum.sa-mp.com/index.php?topic=100530.0

Good Luck.

EDIT: LOL, some of the answers were answered whilst typing this.